[Overclockers.com]

Guide to Delta-T in Water Cooling
by Conumdrum

A water-cooled PC, like any other, can generate a significant amount of heat. Some parts produce massive amounts of heat due to the incredible number of calculations needed to give us what we crave – realistic games, distributed computing projects that might change the future of science and encoding and decoding audio and video, to name just a few. I’m going to focus on two parts of your PC: the CPU and the GPU, as these produce most of the heat. I’ll also touch on a few other critical issues you need to understand.

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[hokiealumnus]

Published and stuck.

[Conumdrum]

Thanks Hokie, I saw you played with it this weekend. Started out as a sticky and boy it became a article. Not because of me, my skilz just aren't for that. Thanks everyone. Another good one for the new folks. Might make our job easier too.

[Crazy Jayhawk]

Can't go below ambient? Maybe "bong" setups aren't as popular as they used to be.

[hokiealumnus]

Bong's don't allow you to go below ambient AFAIK. It's just a form of evaporative cooling isn't it?

[Higdon]

But if we do not ask you stupid questions then how else will you spend your time? Not playing around on your own system I hope. That is for NERDS!

[dustin1706]

Nice article man. Great read for any new watercoolers.

Screaming banshee ROFL

[thorilan]

actually a bong can allow below ambient temps by 1-2C BUT and this is a big BUT they have to be very large and it wont happen during load.

[MySchizoBuddy]

what if you connect the GPU and CPU in parallel. So the cool water from the radiator goes to CPU and GPU in parallel and the output from the GPU and CPU go back in the inlet of the radiator. you will need a T junction to split and join the incoming and outgoing loop

[MattNo5ss]

to OCForums!

It won't make much of a difference because the water temps throughout the loop is always within 1-2C of each other, no matter where you measure the temp. So, water temp after the rad and water temp after the GPU block will be almost the same, maybe 1-2C different.

When splitting into parallel, you have to be careful with flow rate and block restriction to make sure you have enough flow and pressure for the blocks on each split.

[Conumdrum]

Originally Posted by MySchizoBuddy

what if you connect the GPU and CPU in parallel. So the cool water from the radiator goes to CPU and GPU in parallel and the output from the GPU and CPU go back in the inlet of the radiator. you will need a T junction to split and join the incoming and outgoing loop

DT is 100% about your heatload and your generated heat. Your question has NO bearing on the fundamental physics of heat made vs dissipated in a radiator.

No matter if series GPUs make 500 watts of heat or the same cards in parellel making 500 watts of heat.

You STILL end up with the same wattage. And the same required cooling.

Some folks get pretty silly and try to make magic, but physics always wins...........

[MySchizoBuddy]

heat transfer is best if there is a temp difference. for eg.
water at 30C enters one GPU and leaves at 60C this 60C enters the CPU now this already hot water has less heat trapping capability. Thats thermodynamics. If water at 30C enters both GPU and CPU at the same time they both now have the same heat trapping capability. Thats thermodynamics.

According to you a 30C water can remove the same amount of heat as 60C water thats wrong.

[m0r7if3r]

Originally Posted by MySchizoBuddy

heat transfer is best if there is a temp difference. for eg.
water at 30C enters one GPU and leaves at 60C this 60C enters the CPU now this already hot water has less heat trapping capability. Thats thermodynamics. If water at 30C enters both GPU and CPU at the same time they both now have the same heat trapping capability. Thats thermodynamics.

According to you a 30C water can remove the same amount of heat as 60C water thats wrong.

Do you realize just how much heat it would take to raise the temperature of water 30C with as little contact as it makes with the block? It's enormous. You're looking at 1-2C difference MAX from the hottest to the coldest point in your loop, and at that point, you're gonna see more of a difference from flow than from any sort of gain you'd get from having 2C colder water.

[MattNo5ss]

The water reaches an equilibrium, so the water temp differences between components aren't drastic like you're thinking. As I mentioned in my previous post, temp differences are only like 1-2C anywhere in the loop. The heat in watts for each component and the cooling capacity of the rad/fans combine to make the water get to a certain temperature.

[MySchizoBuddy]

I stand corrected. your right. the temp doesn't go high enough to mean much. So flow restriction will play a greater role. series tubing will result in smaller tubing and hence better flow. correct.

[Bojan2801]

Very, very good guide. Thanks

[Modz 4 Higher]

I have read this over and over and over. It's fun

I ROFL when I saw enters GPU at 30c and leaves at 60c I'm like WTF system are you running. Glad that got cleared up

[oli4ei162]

I want to watercool 2x gtx 670, i7 3770k clocked to 4,3 ghz and a maximus v formula maybe also the ram corsair gt 16gb 2133 (just beceause it looks nice) in a nzxt switch case how many rads do i need?

[wagex]

O.O the guide would tell you that...

[oli4ei162]

Common......